1. Field of the Invention
The present invention relates to a timer useful in a microwave oven, a toaster oven or the like for counting desired time of heat cooking.
2. Prior Art
Conventionally, a timer is provided in a microwave oven or the like, and food is heated by functioning heating means of the microwave oven for a predetermined time set by this timer, and when this predetermined time elapses, food heating stops automatically. In such a microwave oven, a heating time is required to be set in the timer every time heating is performed. For example, in a microwave oven having a high-frequency output of approximately 500 W, a heating time of approximately one minute is most frequently used. Accordingly, to simplify the setting operation of heating time, microwave ovens have also been conventionally realized wherein, separately from a mechanical timer, there is provided a so-called electronic one-minute timer or the like having a charge/discharge circuit composed of a resistor, a condenser, a comparator and the like, for distinguishing a level of the output thereof and performing a time counting operation.
Also, a microwave oven having a timer constituted by combining a rotary switch and a microprocessor is known (U.S. Pat. No. 4,849,595).
However, as described above, separate provision of such an electronic timer for the heating time frequently set often raises the price of the microwave oven unduly.